Dismantling keybolt for a propping-up and supporting framework

ABSTRACT

A keybolt for lowering a mold form supporting frame comprises a U-shaped bracket including a semicylindrical bight portion connecting two rigid parallel arms, each comprising a horizontal rectilinear edge constituting a stirrup for supporting an upper telescopic member and a lower edge upwardly inclined from the bight toward the horizontal edge and constituting a ramp for bearing on a pin removably supported by the frame, means spanning said arms to limit transversal movement of the bracket to selectively lower the frame by limited increments.

I United States Patent 1 1 3,632,075

[72] Inventor Enrique Munoz [56] References Cited a n UNITED STATESPATENTS P 1,552,912 9/1925 c011 254/104 [22] Filed Feb. 18, 1970 451Patented Jan. 4, 1972 FOREIGN f T [73] Assignee Entreprlses Devars Naudo8; Cie 342,876 2/1931 Great Brltam 248/354 P Paris, France 584,2201/1947 Great Britain... 248/354 R Pmmy 3533 Primary Examiner-William 11.Schultz t 6910104 A! omey 1m1ne & Sm1ley s41 DISMANTLING KEYBOLT FOR APROPPING-UP gg gg f gal zz3:222?.2 1: f m f AND SUPPORTING FRAMEWORK P Pa 7 CM 3D in Fl cal blght portion connecting two ng d parallel arms,each [52] U S C'l raw g 248/354 P tcomprisinlgfa horizontal rectilinearedge tcjmstitjuting a stiraup or suppo 1ng an upper e escop1c mem r an aower e go 254/ 104 upwardly inclined from the bight toward thehorizontal edge [51] Int. Cl B61111/02 and constituting a ramp forbearing on a pin removably sup- [50] Field of Search 248/351, ported bythe frame, means spanning said arms to limit trans- 354 R, 354 P, 354 S;254/1 1, 104; 182/179 versal movement of the bracket to selectivelylower the frame by limited increments.

PATENTEDJAN M972 SHEET 1 OF 2 FIGA //v wi '0 PATENTEB JAN 4 B72 SHEET 2OF 2 DISMANTLING KEYBOLT FOR A PROPPING-UP AND SUPPORTING FRAMEWORKBACKGROUND OF THE INVENTION For making levelling flooring-slabs or otherappreciably horizontal constructions, recourse is generally had to aframework of which at least the top part is provided with axiallyadjustable members, such as screwjacks, for supporting a mold form.

When the form is put into position, the frameworks are raised, forinstance, by means of telescopic legs, up to an approximate height, thenthe screwjacks are regulated for suitably adjusting the position of theform.

To dismantle the construction it is necessary to reduce the height ofthe framework to a certain extent, so as then to be able to carry out apartial raising, particularly by means of hydraulic jacks, which enablethe disengaging and withdrawing of telescopic legs, then the lowering ofthe framework. To carry out such operation, most frequently one acts onupper screwjacks, so as to lower the table in relation to theconstruction made. This operation is carried out by hand, so that theworkmen are obliged to work at the top part of the framework, whichentails considerable physical strain as well as the risking of more orless serious accidents owing to falling. Furthermore, when the topscrewjack gets out of order, the positioning originally imparted to theform is altered and must then be readjusted.

SUMMARY OF THE INVENTION The present invention overcomes these variousdisadvantages by creating a keybolt enabling the height of a frameworkto be sufiiciently reduced by a simple and speedy operation carried outwithin easy human reach.

According to the invention, the keybolt, slipped transversally between alower clamp of the vertical upright of a framework and a transversal pinengaged in an axially adjustable manner in a telescopic leg slidablymounted inside said upright, is formed by a U-shaped stirrup-piececomprising a semicylindrical core connecting two rigid parallel arms orwings each comprising a horizontal rectilinear edge cooperating withsaid clamp and a sloping edge converging towards said rectilinear edgeto form a ramp cooperating with the removable pin traversing thetelescopic leg.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation of a buildingand maintaining framework device fitted with a keybolt according to theinvention;

FIG. 2 is a partial side elevation showing, on a larger scale, thekeybolt, and

FIG. 3 is a section taken substantially along the line IIIIII of FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION FIG. I shows the applying of thekeybolt, according to the invention, to a framework 1 shown, by way ofexample, in the form of a fixed scaffolding. This fixed scaffoldingconsists of a certain number of building members 2 and respectivelyformed by three tubes 3, 4 and 5 mutually assembled at one of their endsfor extending in three planes, perpendicularly to one another. Theholding of these tubes in their right angular relation is effected byangle-braces 6. The building elements 2, eight in number for instance,are mutually assembled at the free ends of their tubes 3, 4 and 5 toform a rigid framework of parallelipipedic shape comprising fourvertical tubular uprights 3.

The fixed scaffolding thus made is completed by positioning, at thebottom ends of the four vertical uprights, of runway members 7,preferably removable, of telescopic legs 8, and at the top ends of saiduprights of supporting members 9. The runway members 7 can be made byexternal or internal rollers whose spindles are mounted in bearings madelevel with the lower ends ofthe uprights 3. Each telescopic leg 8includes a tube sliding on a corresponding vertical upright which isprovided with a retaining member ensuring the axial locking of said tubein maximum penetration when the fixed scaffolding rests on the runwaymembers. Each leg 8 has a series of transversal holes 8; FIG. 3, forreceiving a pin 11, forming an adjustable abutment on which thecorresponding end of the vertical tubular upright bears when the fixedscaffolding is placed in elevation in relation to the ground. Eachsupporting member 9 comprises a sleeve 12 fixed to the top part of thecorresponding vertical tubular upright. The sleeve 12 is tapped foraccommodating a threaded rod 13 whose top end is able to revolve on acatch 14 made integral with the core of a stirrup-piece I5 whose arms 16rise vertically. The four stirrup-pieces 15 are oriented in pairs forsupporting two parallel girders 17 on which the horizontal table 18rests. Said table can be made in any suitable manner, particularly ofsections 19 for holding shuttering or mold form 20 for making ahorizontal construction or a levelling flooring-slab 21.

To operate the fixed scaffolding described above and raise theshuttering or mold form 20 up to the height corresponding to thebuilding 21 to be effected, various methods can be put into operation.Generally, jacks 22, hydraulic for instance, are adapted on the bottomterminal parts of the tubular uprights, so that their rods 23 cooperatewith shoes 24 able to be axially locked, in an adjustable manner, on thetelescopic legs 8. After positioning the various jacks 22, a supply offluid under pressure is controlled for causing the rods 23 to extend sothat said rods by bearing on the shoe 24, ensure the raising of thefixed scaffolding by extension of the telescopic legs 8. When theapproximate height is reached, the pins 11 are engaged in the telescopiclegs 8 for forming abutments on which the vertical tubular uprightsbear. The support members 9 are then adjusted by means of threaded rods13 for imparting to the table the seating corresponding to theconstruction work 21 to be carried out. The operations for putting intoeffect, such as those described above, also comprise the fitting of thekeybolt, according to the invention, between the pin 11 and clamp 25integral with the corresponding bottom end of the vertical tubularupright of each telescopic leg 8.

According to FIGS. 2 and 3, the keybolt is formed by a U- shapedstirrup-piece 26 or bracket comprising a semicylindrical core or lightportion 27 whose internal radius substantially corresponds to that ofthe telescopic legs 8. The core 27 connects two parallel rigid arms orwings 28 whose length is greater that the diameter of the legs 8. Thearms 28 have aligned holes 29a, 29b, 290, provided for receiving alocking pin 30 having a handle 31 secured to a chain or other flexibleconnection 32 with one of the arms or wings 28.

Each arm 28 has a rectilinear course 33, extending in the transversalplane defining one of the edges of the semicylindrical core or light 27,and a second course 34 sloped in a converging manner towards the course33 and intercepting the second transversal plane defining the other edgeof the semicylindrical core 27, but beyond the imaginary diametral planeof said core. The course 34 is made as a function of the length of thearms or wings 28 so as to have a same relatively slight slope and makeramps for cooperating with the terminal parts of the pin 11 projectingon either side of the telescopic leg 8.

After raising the framework 1 by means of the jacks 22, the variouskeybolts are inserted between the clamps 25 to rest by their ramps 34 onthe pins 11 previously engaged in the corresponding holes of thetelescopic legs 8. The engaging of each keybolt is done so that the core27 is appreciably applied against the corresponding peripheral surfaceof the telescopic leg 8. The transversal locking of each keybolt is thenassured by positioning the locking pin 30 in the holes 29a made in thearms or wings 28 for limiting, with the interior peripheral surface ofthe core 27, a passage section sufficient for the telescopic leg 8. Inthis position, in which the pins 11 cooperate with the beginning part ofthe sloped ramps 34, the keybolts 26 cannot be subjected to anyaccidental transversal or axial displacement and, consequently, occupy adefinite position which enables the supply to thejacks 22 to be reversedso as to make the framework 1 rest by the clamps 25 on the keybolts 26bearing on the terminal parts of the pins 11.

When it is necessary to proceed to dismantle the building ef fected, theworkmen in charge of this operation disengage the locking pins 30 of thekeybolts 26 from the holes 29a then put them back again in the holes 2%.Each keybolt 26 is then moved in the direction of the arrow f byrepeated blows given level with the terminal parts of the arms or Wings18. The transversal sliding of each keybolt 26 is easily done betweenthe clamp 25 and the pin 11 owing to the presence of the ramps 34 whoseslope is chosen for preventing a sudden unexpected disengaging. As thekeybolts 26 are progressively withdrawn, the sloped ramps 34 cause theprogressive lowering of the framework which is thus subjected to aslight downward vertical displacement for the removal, without suddenmovement, of the mold form 20 of the building 21. The transversaldisplacement of each keybolt is normally carried out up to the momentwhen the locking keybolt 30, engaged in the holes 2911, is brought intocontact with the telescopic leg 8.

in addition to the abutment function limiting the amplitude of thetransverse] sliding of the keybolts 26 during dismantling, it should benoticed that the locking pins 30 also form safety members opposing anyrisk of complete disengagement, which might have the effect ofsubjecting the framework to an abrupt fall on to the pins 1 1.

According to the applications, the first transversal sliding stage ofeach pin can be followed by an identical stage by disengaging thelocking pin 30 from the holes 29b for reintroduction in the holes 29c.This gives the benefit of an additional transversal sliding amplitudeenabling a more considerable lowering vertical movement of theframework.

When the transversal displacement of the various keybolts is done, thejacks 22 are supplied with pressure fluid for extending piston rods 23raising the framework to an extent just sufficient for relieving thevarious pins 11 which can thus be disengaged from the telescopic legs 8.The complete lowering of the propping-up framework is then controlled bymeans of the jacks 22, contingently combined with the progressivedisplacement of the pins 11 in relation to the telescopic legs 8, in thecase where it is necessary to provide safety elements capable ofavoiding failures of jacks 22.

As can be seen from the foregoing, the complete lowering of theframework is thus obtained without disturbing the seating of the moldform support and solely by means of simple operations carried outwithout danger at a height within easy human reach.

lclaim:

1. A keybolt for propping a vertically extensible framework and enablingselective lowering thereof for dismantling thereof, comprising a rigidU-shaped bracket for straddling a lower leg of the framework andsupported by a pin in said leg to constitute a stirrup for supporting anupper leg telescoped on the lower leg, said bracket including a bightportion connecting two parallel arms each having a horizontalrectilinear upper edge and a lower edge inclined upwardly from saidbight portion toward the upper edge, said upper edges constituting thesupport stirrup and said lower edges constituting a ramp engageable withthe supporting pin for lowering said stirrup when the bracket is movedtransversely of the leg and means spanning said arms to limit transversemovement of the bracket.

2. A keybolt according to claim 1 wherein said arms are of a lengthsubstantially greater than the transverse dimensions of the frameworkleg to be straddled, said means comprising a pair of aligned holes insaid arms, said holes being spaced from said bight portion a distancesubstantially equal to the transverse dimensions of the leg and aretainer removably inserted in said pair of holes to retain said bracketin full supporting position or permit transverse movement of saidbracket rela tive to the leg to enable lowering of said stirrup as theramp edges slide on the leg supported pin.

. A keybolt according to claim 2 wherein said arms are of a lengthsubstantially greater than the transverse dimensions of the frameworkleg to be straddled, said arms having a plurality of said pairs ofaligned holes spaced longitudinally of said arms whereby said retainermay be removably inserted selectively in a pair of holes to retain saidbracket in full supporting position or permit limited transversemovement of said bracket relative to the leg to enable an incrementallowering of said stirrup as the ramp edges slide on the leg supportedpin.

4. A keybolt according to claim 3 wherein there are three of said pairsof holes.

5. A keybolt according to claim 2 comprising a flexible connectorsecuring said retainer to said bracket.

6. A keybolt according to claim 1 wherein said bight portion issemicircular and has an internal radius substantially equal to theradius of the framework leg.

7. A keybolt according to claim 1 wherein said bight portion issemicylindrical with the ends thereof contiguous with said arms at adiametrically disposed plane, said inclined lower edges of said armsintersecting the lower edge of said bight portion beyond said plane.

1. A keybolt for propping a vertically extensible framework and enabling selective lowering thereof for dismantling thereof, comprisiNg a rigid U-shaped bracket for straddling a lower leg of the framework and supported by a pin in said leg to constitute a stirrup for supporting an upper leg telescoped on the lower leg, said bracket including a bight portion connecting two parallel arms each having a horizontal rectilinear upper edge and a lower edge inclined upwardly from said bight portion toward the upper edge, said upper edges constituting the support stirrup and said lower edges constituting a ramp engageable with the supporting pin for lowering said stirrup when the bracket is moved transversely of the leg and means spanning said arms to limit transverse movement of the bracket.
 2. A keybolt according to claim 1 wherein said arms are of a length substantially greater than the transverse dimensions of the framework leg to be straddled, said means comprising a pair of aligned holes in said arms, said holes being spaced from said bight portion a distance substantially equal to the transverse dimensions of the leg and a retainer removably inserted in said pair of holes to retain said bracket in full supporting position or permit transverse movement of said bracket relative to the leg to enable lowering of said stirrup as the ramp edges slide on the leg supported pin.
 3. A keybolt according to claim 2 wherein said arms are of a length substantially greater than the transverse dimensions of the framework leg to be straddled, said arms having a plurality of said pairs of aligned holes spaced longitudinally of said arms whereby said retainer may be removably inserted selectively in a pair of holes to retain said bracket in full supporting position or permit limited transverse movement of said bracket relative to the leg to enable an incremental lowering of said stirrup as the ramp edges slide on the leg supported pin.
 4. A keybolt according to claim 3 wherein there are three of said pairs of holes.
 5. A keybolt according to claim 2 comprising a flexible connector securing said retainer to said bracket.
 6. A keybolt according to claim 1 wherein said bight portion is semicircular and has an internal radius substantially equal to the radius of the framework leg.
 7. A keybolt according to claim 1 wherein said bight portion is semicylindrical with the ends thereof contiguous with said arms at a diametrically disposed plane, said inclined lower edges of said arms intersecting the lower edge of said bight portion beyond said plane. 